8. BioShockWhy it's scary: First, there are the obvious elements. There are the mutated inhabitants of Rapture and the disturbing story elements that you can uncover that reveal just how they got this way. Just thinking about some of those audio diaries is enough to send shivers down our spine all over again. Then there's the unnatural hunger of the Little Sisters and the agonizing choice you're presented with whenever you capture one. That all of that takes place within a world of shattered beauty and moody sound design makes it that much sweeter. In the end though, it's the all-too-human story of how Andrew Ryan's ambitious vision is perverted that's really at the heart of the terror here. Well, that and the bit with the golf club.

7. Dead SpaceWhy it's scary: Isolation is one of the key elements of horror, and you can hardly get any more isolated than when you're in the cold blackness of outer space. Players join up with a maintenance crew sent to repair the communications equipment on a mining ship. When they arrives, they find that the entire crew has been viciously mutilated by unknown beings. Unfortunately, those beings soon make an appearance, killing off most of the repair crew and leaving the player isolated from the few survivors. Using only an arsenal of repurposed mining equipment, you'll have to fight your way through increasingly hostile and deadly enemies in order to survive.